Electronic Load: What is it and how do I use one?
An electronic load is a type of instrument that applies a voltage and sinks current. Also known as a programmable load, these AC or DC electronic loads can be used by power supply, battery, solar, wind, or other manufacturers who want to thoroughly test their power sources. Manufacturers of these types of products need to test their supplies dynamically, rapidly increasing and decreasing the load in a repeatable fashion, programmable electronic loads make this much easier than configuring resistors or resistive elements for each test. Devices must be tested for their various states of operation. Batteries must often also be tested for hundreds and thousands of cycles to ensure longevity and to determine expected lifetime. Electronic loads are used by car battery manufacturers, fuel-cell manufacturers, cell-phone manufacturers, solar panel manufacturers, and in other industries where power must be tested and they are useful to determine characteristics and providing discharge test data for engineers. Electronic load systems are also used for aerospace, commercial electronics, defense, and by utilities where special modes of operation are required and need to be tested.
Most DC electronic loads available use on transister/FET or an array of parallel connected transistors/FET’S or IGBT’s in order to act as a variable resistor. These are typically mounted onto a heat sink and cooled with fans. The electronic load shown above in the image, and others available from Circuit Specialists offer programmability and constant power, constant current, and constant voltage modes for greater testing flexibility. They can also be controlled remotely via RS232 and export data for logging. Circuit Specialists offers DC Programmable Electronic Loads from 100W all the way up to 3KW for high-power testing applications.
DC loads can be used to simulate another type of load such as a DC motor. They can be pulsed very rapidly to mimic switching on and off of a DC motor or other DC load. They can also be used to draw small amounts of power to simulate a slow drain of a battery to some external load.
Manufacturers that use an electronic load to test their equipment prior to production will have a competitive advantage and will produce equipment that will be more precise and robust.